This is a 2-way power jack splitter that allows you to split one 2.1mm/5.5mm DC barrel jack into two. This cable makes it easy to power two separate devices from one power supply.

Prototyping board (2"x2.75")These prototyping PCBs are perfect for prototyping circuits, hence their name. They are somewhat of an intermediary between solderless breadboards and making a real PCB. They are cheap and work great!

2.4GHz Wireless TransceiverThis board has a 2.4GHz wireless transceiver. In order to establish a communication link, you will need to buy two boards. NRF24L01+ based boards are very popular and many tutorials and libraries can be found online.

This is a standard 4-Digit 7-Segment Display. To simplify your interface to a 7-segment display with multiple digits, consider using an LED Display Driver.

ATMEGA8-16PUThe ATMEGA8-16PU is a popular ATMEL microcontroller commonly used for Arduino projects. The ATMEGA8-16PU can operate up to 16MHz, has a 10-bit ADC, 8 KB of program memory, 1 KB of data RAM, and supports SPI and USART.

DS18B20 Waterproof Temperature ProbeThis is a waterproof temperature probe with the DS18B20 temperature sensor inside it and can be used to precisely and accurately measure temperature. This sensor can be easily integrated with Arduino by using the OneWire library. The red wire is VCC, black is GND, and yellow is data.

MAX7219CNG LED Display DriverThe MAX7219CNG is a compact, serial input/output common-cathode display driver used to interface microprocessors to 7-segment numeric LED displays of up to 8 digits, bar-graph displays, or 64 individual LEDs. Included on-chip are a BCD code-B decoder, multiplex scan circuitry, segment and digit drivers, and an 8x8 static RAM that stores each digit. Only one external resistor is required to set the segment current for all LEDs.

Pro MiniThe Pro Mini is a great little Arduino-Compatible board. The small form factor makes it perfect for use in projects where space is a concern.

The Pro Micro is similar to the Pro Mini, but uses the ATmega32U4, which allows USB connectivity to be added on-board. The Pro Micro is considered to be the replacement for the Pro Mini, but costs slightly more.

Sharp IR Sensor (GP2Y0A02YK0F)The GP2Y0A02YK0F is Sharp's top of the line IR distance sensor. It has a range of 20-150cm (~8in-5ft) and an easy to use analog output. Unlike many stores that sell this sensor, we include a cable with it!

4-Digit 7-Segment Display Board (Common Anode)This is a standard 4-Digit 7-Segment Display, but on a breakout board for ease of use. The LED segments are red and are 0.36" tall. The board has current limiting resistors built-in, so no external resistors are necessary - just connect pins from your microcontroller to the board and you're ready to go!

TCS230 Color Sensor ModuleThis board uses the TCS230 sensor to detect the color of objects. The board outputs a 0-5V analog signal corresponding to the measured color and can be directly interfaced with a microcontroller.

HR202 Humidity Sensor ModuleThis module detects the humidity of the surrounding environment and outputs both analog and digital signals. The board has a potentiometer which allows the sensitivity to be adjusted.

OV7670 CMOS CameraThe OV7670 is a popular and inexpensive CMOS Camera. It has high sensitivity, allowing it to work well in low light environments, a low operating voltage, and a standard SCCB interface (compatible with I2C).

PIR Motion SensorThis is an easy to use motion sensor. PIR sensors are used to detect motion caused by humans or pets and are great for determining whether people have entered or left a room.

This is a 5mm common anode RGB LED. An RGB LED is like a regular LED, but with three different colors (red, green, and blue) all in a single package. This makes it easy to not only change the color of an LED, but also to create intermediate colors by "blending" the three colors together.

TCRT5000 Reflective Optical SensorThe TCRT5000 is a popular IR sensor that combines an IR LED and IR receiver in one easy to use package. This sensor is often used for line follower robots.

Hall effect sensor - US5881LUAThe US5881LUA is a hall effect sensor, which is used to detect whether a magnet is near. Hall effect sensors are often used on rotary encoders and position sensors for things like switches.

DC Barrel Breadboard Power JackThis barrel power jack is extremely nice as it will fit into both PCBs and breadboards. The jack is designed for plugs that have a 2.1mm inner diameter and 5.5mm outer diameter (by far the most commonly used size for power connectors).

FTDI USB-TTL Breakout For ArduinoThis breakout board is an easy-to-use USB-TTL converter. A jumper on the board allows it to be configured to operate at either 3.3V or 5V (both power output and I/O level). The board has a standard USB connector on one end and a 6-pin female header on the other.

Small Stepper MotorThis is a small but powerful bipolar stepper motor, great for CNC and robotics applications.

This small, light ball caster from Pololu uses a 3/8" diameter plastic ball. The height of the assembled kit ranges from 0.4" to 0.6".

This ball caster kit includes a black ABS housing, a 3/8" diameter plastic ball, two spacers (1/16" and 1/8" thick), and two #2 screw sets. The total height of the ball caster, 0.4", can be increased to about 0.6" using the included spacers. The two included #2 screws can be used to mount the ball caster to your chassis (the distance between the screw holes is 0.53").

Note that our ball casters are designed for small robots; they are not intended to bear more than a few pounds. With more weight than this, friction between the ball and the housing will probably keep it from rolling well.

This ball caster kit includes a black ABS housing, a 1/2" diameter plastic ball, two spacers (1/16" and 1/8" thick), and two #2 screw sets. The total height of the ball caster, 0.53", can be increased to about 0.7" using the included spacers. The two included #2 screws can be used to mount the ball caster to your chassis (the distance between the screw holes is 0.58").

Note that our ball casters are designed for small robots; they are not intended to bear more than a few pounds. With more weight than this, friction between the ball and the housing will probably keep it from rolling well.